Electrochemical polishing method

ABSTRACT

An electrochemical polishing method is provided for polishing a workpiece having at least one sharp object. According to the present invention, the electrolyte is driven to flow to the sharp object and the electrochemical processing is performed for polishing the sharp object.

FIELD OF THE INVENTION

The present invention relates generally to an electrochemical process, and particularly to an electrochemical polishing apparatus and an electrochemical polishing method for polishing a workpiece.

BACKGROUND OF THE INVENTION

The methods for polishing sharp objects include chemical and electrochemical polishing processes. Nonetheless, electrochemical polishing processes tend to blunt the sharp ends of sharp objects, that causes the expected function of the sharp objects being unachievable. In order to keep the sharp ends of sharp objects, electrochemical polishing processes are normally not adopted. In addition, the polishing efficiency of chemical polishing processes is low; chemical materials are detrimental to the environment and human health. Thereby, chemical polishing processes are not suitable for polishing sharp objects. How to polish sharp objects using electrochemical processes has become a challenge in electrochemical processing.

SUMMARY

An objective of the present invention is to provide an electrochemical polishing method for polishing a workpiece.

An electrochemical polishing method polishing the workpiece having at least one sharp object according to the present invention comprises: providing the electrolyte flowing to the sharp object; and performing electrochemical processes; where the electrolyte flows from the sharp end of the sharp object to the sharp body of the sharp object for reducing the difference between the first polished amount of the sharp end and the second polished amount of the sharp body. Further, the electrochemical polishing method according to the present invention can drive the electrolyte to flow by disturbing or projecting the electrolyte.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of the electrochemical polishing apparatus according to the first embodiment of the present invention;

FIG. 2 shows a cross-sectional view of the electrochemical polishing apparatus according to the first embodiment of the present invention;

FIG. 3 shows an enlarged view of the zone A in FIG. 2;

FIG. 4 shows a schematic diagram of the electrochemical polishing apparatus according to the second embodiment of the present invention;

FIG. 5 shows a schematic diagram of the electrochemical polishing apparatus according to the third embodiment of the present invention;

FIG. 6A shows a schematic diagram of the electrode according to the first embodiment of the present invention;

FIG. 6B shows a schematic diagram of the electrode according to the second embodiment of the present invention;

FIG. 7A shows a schematic diagram of the electrode according to the third embodiment of the present invention;

FIG. 7B shows a schematic diagram of the electrode according to the fourth embodiment of the present invention;

FIG. 7C shows a schematic diagram of the electrode according to the fifth embodiment of the present invention; and

FIG. 8 shows a flowchart of the electrochemical polishing method according to an embodiment of the present invention.

DETAILED DESCRIPTION

In order to make the structure and characteristics as well as the effectiveness of the present invention to be further understood and recognized, the detailed description of the present invention is provided as follows along with embodiments and accompanying figures.

Please refer to FIG. 1 and FIG. 2, which show a schematic diagram and a cross-sectional view of the electrochemical polishing apparatus according to the first embodiment of the present invention. As shown in the figures, the present invention provides an electrochemical polishing apparatus 1 used for polishing a workpiece 30 having at least one sharp object 320. The electrochemical polishing apparatus 1 comprises an electrode 10 and a power supply unit 20. The electrode 10 corresponds to a surface 310 of the workpiece 30. The electrode 10 and the workpiece 30 are spaced by a distance D1. According to an embodiment of the present invention, the distance D1 is approximately 8 to 15 millimeters (mm). The electrode 10 has a plurality of hollow-out parts 110 corresponding to the surface 310 of the workpiece 30. The plurality of hollow-out parts 110 of the electrode 10 allow an electrolyte 40 to flow through and to the sharp objects 320 of the workpiece 30. By driving the electrolyte 40 to flow through the plurality of hollow-out parts 110, the flow field of the electrolyte 40 can be more uniform. Thereby, when the sharp objects 320 are being polished, the sharp ends 321 of the sharp objects 320 can be less blunted. The both electrodes of the power supply unit 20 are coupled to the electrode 10 and the workpiece 30, respectively, for performing electrochemical processes. Hence, by using the electrochemical polishing apparatus 1, the workpiece 30 having the sharp objects 320 can be polished. According to an embodiment of the present invention, the voltage supplied by the power supply unit 20 ranges between 5 and 8 volts.

According to the present embodiment, the cathode of the power supply unit 20 is coupled to the electrode 10 whereas the anode is coupled to the workpiece 30. According to an embodiment of the present invention, the electrode 10 is a metal plate having the plurality of hollow-out parts 110. The arrangement of the plurality of hollow-out parts 110 can be symmetric, asymmetric, or staggered. Each hollow-out part 110 can be a hole or an opening. The shape of each hollow-out part 110 can be circular (as shown in FIG. 6A), triangular, quadrangular (as shown in FIG. 6B), rectangular, or any other polygons. The plurality of hollow-out parts 110 according to the present embodiment are staggered. The hollow-out parts 110 in the upper row are staggered to those in the lower row. Each hollow-out part 110 is circular. According to an embodiment of the present invention, the material of the electrode 10 can be, but not limited to, titanium. Alternatively, any other metal can be adopted as well.

Please refer to FIG. 3, which shows an enlarged view of the zone A in FIG. 2. As shown in the figure, the electrolyte 40 is in the flowing state. The electrolyte 40 passes through the plurality of hollow-out parts 110 of the electrode 10 and flows to sharp objects 320 of the workpiece 30. When the electrolyte 40 flows through the electrode 10, the flow of the electrolyte 40 is limited by the electrode 10 and is divided to pass through the plurality of hollow-out parts 110. Consequently, a more uniform flow field of the electrolyte 40 is generated. The electrolyte 40 does not flow to only a portion of the sharp objects 320 concentratively. Instead, the electrolyte 40 can flow to the plurality of sharp objects 320 uniformly.

As shown in FIG. 3, the electrolyte 40 continues to flow towards the sharp object 320. The electrolyte 40 flows from the sharp end 321 of the sharp object 320 to the sharp body 322 of the sharp object 320. Thereby, the electrolyte 40 will carry away the products of the electrochemical polishing, preventing accumulation of the products on the sharp body 322 of the sharp object 320 and facilitating full contact between the sharp body 322 and the electrolyte 40. Thus, the difference between a first polished amount (a first ionized amount) of the sharp end 321 and a second polished amount (a second ionized amount) of the sharp body 322 can be reduced. Accordingly, the variation in the taper of the sharp object 320 can be reduced, which means that sharp end 321 of the sharp object 320 can be less blunted.

Please refer again to FIG. 1 and FIG. 2. According to the present embodiment, the electrochemical polishing apparatus 1 further comprises a flow equalizer 70 disposed between the electrode 10 and the workpiece 30. The flow equalizer 70 and the workpiece 30 are spaced by a distance D2 such that the flow equalizer 70 can provide a relatively uniform flow field for the workpiece 30. By controlling the distance D2, the gap for the electrolyte 40 to flow away from the workpiece 30 can be controlled and thus carrying away the products. It is known from the above description that according to the processing requirements, the distance D1 between the electrode 10 providing the electric field and the workpiece 30 and the distance D2 between the flow equalizer 70 regulating the flow and the workpiece 30 can be controlled, respectively. Thereby, by controlling the distances D1, D2, the electrochemical polishing apparatus 1 can be operated with ease. According to an embodiment of the present invention, by using a fixture (not shown in the figures), the flow equalizer 70 can be disposed between the electrode 10 and the workpiece 30.

Besides, the flow equalizer 70 includes at least one hollow-out part 710. According to the present embodiment, the flow equalizer 70 includes a plurality of hollow-out parts 710 corresponding to the plurality of sharp objects 320 of the workpiece 30, respectively. Moreover, the flow equalizer 70 can be an insulator, so that the flow equalizer 70 can shelter a part of electric field. The part of electric field not corresponding to the plurality of hollow-out parts 710 will be sheltered. Thereby, the processed amount at the parts shouldn't be processed can be reduced. The electrolyte 40 passing through the plurality of hollow-out parts 110 of the electrode 10 passes through the plurality of hollow-out parts 710 of the flow equalizer 70 and flows to the plurality of sharp objects 320. When the electrolyte 40 flows through the flow equalizer 70, the flow of the electrolyte 40 is limited by the flow equalizer 70. The flow of the electrolyte 40 is divided by the plurality of hollow-out parts 710 and led to the corresponding plurality of sharp objects 320. Thereby, the electrolyte 40 can flow to each sharp object 320 more uniformly. In addition, the flow equalizer 70 can be a plate or a mesh. The shape of the plurality of hollow-out parts 710 is not limited.

Please refer to FIG. 4, which shows a schematic diagram of the electrochemical polishing apparatus according to the second embodiment of the present invention. As shown in the figure, according to the present embodiment, the electrochemical polishing apparatus 1 further comprises an electrolyte driving unit 50 and an electrolyte tank 60. The electrolyte tank 60 accommodates the electrode 10, the workpiece 30, and the electrolyte driving unit 50. The electrolyte 40 fills the electrolyte tank 60. According to the present embodiment, the electrolyte driving unit 50 is an electrolyte disturbing device 50A, which can spin and disturb the electrolyte 40. By driving the electrolyte 40 to flow, the electrolyte 40 is driven to pass through the plurality of hollow-out parts 110 of the electrode 10 and the plurality of hollow-out parts 710 of the flow equalizer 70, and flow to the plurality of sharp objects 320 of the workpiece 30.

Please refer to FIG. 5, which shows a schematic diagram of the electrochemical polishing apparatus according to the third embodiment of the present invention. As shown in the figure, according to the present embodiment, the electrolyte driving unit 50 is an electrolyte projecting device 50B, which projects the electrolyte 40 to the electrode 10 and thus driving the electrolyte 40 to pass through the plurality of hollow-out parts 110 of the electrode 10 and the plurality of hollow-out parts 710 of the flow equalizer 70, and flow to the plurality of sharp objects 320 of the workpiece 30.

Please refer to FIG. 6A and FIG. 6B, which show schematic diagrams of the electrode according to the first and second embodiments of the present invention. As shown in the figures, the electrode 10 is a metal plate having a plurality of hollow-out parts 110. According to the embodiment shown in FIG. 6A, the arrangement of the plurality of hollow-out parts 110 of the electrode 10 is symmetric and rectangular. In addition, the shape of each hollow-out part 110 is circular. According to the embodiment shown in FIG. 6B, the arrangement of the plurality of hollow-out parts 110 is the same as the staggered arrangement of the plurality of hollow-out parts 110 according to the embodiment shown in FIG. 1. In addition, the shape of each hollow-out part 110 is rectangular. Furthermore, the arrangement of the plurality of hollow-out parts 110 of the electrode 10 can be asymmetric and irregular. The shape of the plurality of hollow-out parts 110 can be others. The present invention does not limit the pattern of the electrode 10.

Please refer to FIGS. 7A to 7C, which show schematic diagrams of the electrode according to the third to the fifth embodiments of the present invention. As shown in the figures, the electrode 10 is a metal mesh. According to the embodiment of FIG. 7A, the electrode 10 is a metal expandable mesh with each hollow-out part 110 having a shape close to a rhombus. According to the embodiment of FIG. 7B, the electrode 10 is a metal mesh formed by a plurality of stacked metal stripes. The shape of each hollow-out part 110 is rectangular. According to the embodiment of FIG. 7C, the electrode 10 is a metal mesh formed by weaving a plurality of metal stripes. The shape of each hollow-out part 110 is rectangular. The present invention does not limit the pattern of the metal meshes. The flow equalizer 70 according to the above embodiment can be an expandable mesh or a woven mesh as well. Nonetheless, the flow equalizer 70 is not limited to metal meshes.

Please refer to FIG. 8, which shows a flowchart of the electrochemical polishing method according to an embodiment of the present invention. As shown in the figure, the present embodiment illustrates the electrochemical polishing method according to the present invention. The electrochemical polishing method according to the present invention polishes the workpiece 30 having at least one sharp object 320. As shown in the step S1, provide the electrode 10 having the plurality of hollow-out parts 110 corresponding to the workpiece 30. As shown in the step S2, provide the electrolyte 40 passing through the plurality of hollow-out parts 110 and flowing to the sharp object 320. As shown in step the S3, supply power to the electrode 10 and the workpiece 30 for performing electrochemical processes. Thereby, polishing can be performed for the sharp object 320. In the step S1, the electrode 10 and the workpiece 30 are spaced by the distance D. Moreover, according to the electrochemical polishing method of the present invention, the flow equalizer 70 can be further disposed between the electrode 10 and the workpiece 30. The flow equalizer 70 has at least one hollow-out part 710 corresponding to the at least one sharp object 320 of the workpiece 30, respectively. The electrolyte 40 further passes through the hollow-out part 710 of the flow equalizer 70 and flows to the sharp object 320.

Besides, the step S2 further includes projecting the electrolyte 40 to the electrode 10 or disturbing the electrolyte 40 for driving the electrolyte 40 to pass through the plurality of hollow-out parts 110 of the electrode 10 and flow to the sharp object 320. The electrolyte 40 flows from the sharp end 321 to the sharp body 322 of the sharp object 320 for reducing the difference between the first polished amount of the sharp end 321 and the second polished amount of the sharp body 322. In addition, the electrochemical polishing method according to the present invention can further adjust the processing parameters, for example, the flow rate of the electrolyte 40, the voltage intensity or current intensity of the power, or the processing time, and thus adjusting the taper of the sharp object 320.

To sum up, the present invention drives the electrolyte to flow and generates the relatively uniform flow field of the electrolyte. The electrolyte flows to the sharp object. Thereby, the electrolyte can carry away the products and prevent accumulation of the products on the sharp body of the sharp object. Then the sharp body can contact the electrolyte, enabling both of the sharp end and the sharp body of the sharp object to be polished and reducing the taper variation of the sharp object. Thereby, the sharp object can be less blunted. Moreover, the parameters of the electrochemical processing can be adjusted and hence adjusting the angle and shape of the sharp object.

Accordingly, the present invention conforms to the legal requirements owing to its novelty, nonobviousness, and utility. However, the foregoing description is only embodiments of the present invention, not used to limit the scope and range of the present invention. Those equivalent changes or modifications made according to the shape, structure, feature, or spirit described in the claims of the present invention are included in the appended claims of the present invention. 

What is claimed is:
 1. An electrochemical polishing method, polishing workpiece having at least one sharp object, comprising: providing electrolyte flowing to said sharp object; and performing electrochemical processes; wherein said electrolyte flows from sharp end of said sharp object to sharp body of said sharp object for reducing the difference between first polished amount of said sharp end and second polished amount of said sharp body.
 2. The electrochemical polishing method of claim 1, further adjusting at least one processing parameter for adjusting the angle of said sharp object.
 3. The electrochemical polishing method of claim 2, wherein said processing parameter includes the flow rate of said electrolyte, the voltage intensity or current intensity of said electrochemical processing, or the processing time.
 4. The electrochemical polishing method of claim 1, further providing electrode having a plurality of hollow-out parts corresponding to said workpiece, and said electrolyte passing through said plurality of hollow-parts and flowing to said sharp object.
 5. The electrochemical polishing method of claim 4, further disposing flow equalizer between said electrode and said workpiece, said flow equalizer having at least one hollow-out part corresponding to said at least one sharp object of said workpiece, respectively, and said electrolyte further passing through said at least one hollow-out part of said flow equalizer and flowing to said sharp object.
 6. The electrochemical polishing method of claim 5, wherein said flow equalizer and said workpiece are spaced by a distance.
 7. The electrochemical polishing method of claim 4, further projecting said electrolyte to said electrode, and said electrolyte passing through said plurality of hollow-out parts of said electrode and flowing to said sharp object.
 8. The electrochemical polishing method of claim 4, further disturbing said electrolyte for driving said electrolyte to pass through said plurality of hollow-out parts of said electrode and flow to said sharp object.
 9. The electrochemical polishing method of claim 4, wherein said electrode and said workpiece are spaced by a distance.
 10. The electrochemical polishing method of method 4, wherein said electrode is a metal mesh or a metal plate.
 11. The electrochemical polishing method of claim 4, wherein said plurality of hollow-out parts are arranged symmetrically.
 12. The electrochemical polishing method of claim 4, wherein said plurality of hollow-out parts are arranged asymmetrically.
 13. The electrochemical polishing method of claim 4, wherein the material of said electrode is titanium. 